Behaviour of hlon and hlat members on the Sun is not documented

[Gareth Rees]

Like other bodies, an object representing the Sun has hlon and hlat members, but unlike other bodies, these do not give the heliocentric longitude and latitude of the Sun (which would be meaningless). Instead, these give the heliocentric longitude and latitude of the Earth.

This exceptional behaviour should be described in the PyEphem documentation, so that (1) users are not confused when they attempt (erroneously) to find the heliocentric coordinates of the Sun; and (2) users who want to compute the heliocentric coordinates of the Earth can figure out how to do it. (See this question on Stack Overflow <http://stackoverflow.com/questions/5881897/how-to-calculate-longitude-using-pyephem> for a user having the first kind of trouble.)

(I could easily be wrong about the Sun's hlon and hlat—but my confusion could be addressed by documenting their true behaviour!)

[Brandon Rhodes (brandon-rhodes)]

Thank you for the idea of clarifying this! The "hlon" and "hlat" attributes now have slightly more extensive documentation that tries to cover this, in the new 3.7.5.1 that I am releasing this evening. Thanks!